I. Field
The present disclosure relates generally to wireless communication, and more specifically to techniques for allocating and using transmission resources in a multi-input multi-output (MIMO) wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication content such as voice, video, packet data, messaging, broadcast. These wireless systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA) systems.
A wireless communication system may include a number of base stations that can support communication for a number of user equipments (UEs). A base station may include multiple transmit and/or receive antennas. Each UE may include multiple transmit and/or receive antennas. In certain designs, such as the Release-8 and Release-9 versions of the Long Term Evolution (LTE) standard, a base station may perform pilot and data transmissions using data transmission techniques such as beamforming, using precoding matrices chosen based on an estimate of the channel between the UE and the base station. However, for fast moving UEs, or when the channel is rapidly changing, the actual channel during a transmission may be significantly different from the calculated estimate of the channel. It may be desirable to improve the throughput when transmitting over fast changing channels.